His agent John Kelly said the actor died at a hospital near his home in Fort. Lauderdale, Florida, where he was being treated for pneumonia.

Canadian-born Leslie came to Hollywood in the mid-1950s after performing in 150 live television dramas in New York.

He quickly became known as a serious actor, although behind the camera he was a prankster - an aspect of his personality never exploited until disaster spoof Airplane! was released in 1980 and became a huge hit.

His lines in Airplane! became legendary. He played the doctor aboard a plane in which the pilots, and some of the passengers, become violently ill. When he asks a passenger if he can fly the plane, the man replies; "Surely you can't be serious."

Nielsen responds: "I am serious, and don't call me Shirley."

After Airplane!'s success, film-making trio Jim Abrahams, David and Jerry Zucker cast their new-found comic star as Detective Drebin in a TV series, Police Squad, which sent up Dragnet and other cop shows. But despite good reviews, ABC cancelled it after only six episodes.

"It didn't belong on TV," Leslie later commented. "It had the kind of humour you had to pay attention to."

Then the Zuckers and Abrahams converted the series into a feature film, The Naked Gun, with George Kennedy, OJ Simpson and Priscilla Presley as Nielsen's co-stars. Its huge success led to sequels The Naked Gun 2 1/2 and The Naked Gun 33 1/3.